The most important factor is that anyone in the home knows how, and can operate any of them quickly and effectively.
A 10lb unit might prove unwieldy for a lot of your kids, or some women (and some men!) - it's not a matter of carrying it, but holding it in position while aiming, and maintaining it, possibly one armed, while the other aims.
No matter which you get, make sure everyone who lives there knows where it is and how to operate it. Even how to remove the strap/bracket holding it in place - those things take expensive extra seconds in an emergency.
As someone who was home alone in my teens and caused a kitchen fire...I figure it out pretty but it could easily have not turned out so well.